Derryvree’s Threeleaf Fen
Archived: 27 September 2026
At around 30,555 BCE, Ireland lay within the unstable middle phase of the last glacial period, not a precisely datable year. Derryvree’s freshwater deposits, preserved between glacial tills in County Fermanagh, record a local ice-free wetland between roughly 36,900 and 31,700 years ago. Its treeless tundra-like environment supported sedges, mosses, aquatic plants, willow and juniper amid severe seasonal conditions. Castlepook Cave in County Cork yielded diverse MIS 3 fauna, including mammoth, reindeer and hyaena. A marked reindeer femur may indicate human carcass processing, but settlement remains unproven. These scarce records show biologically active landscapes before later ice-sheet expansion transformed Ireland.